n.化石；石化作用；嚇呆
The petrified wood fossils have been preserved for millions of years by the process of petrification, a process which turns the wood into quartz crystal, harder than steel. 石化木材的化石自石化過程起，已經(jīng)歷了數(shù)百萬年，石化過程會將木材轉變成為比鋼鐵還要堅硬的石英晶體。
